The present invention relates to a turbine temperature sensor probe assembly projecting from the surface of a turbine inlet into the air flow stream with a post or projection supported upstream of a temperature sensor probe to provide protection for the temperature sensor probe from airborne debris. The post is spaced at a distance such that the air flow is separated as it reaches the temperature sensor probe, to provide for a more rapid sensor response changes in inlet temperature.
A critical factor for a turbine engine temperature sensor is time response. In most applications, it is desired to have a fast time response, meaning the faster that a temperature sensor can respond to a change in temperature of a flowing media such as air, or other fluids, the better. The temperature sensor typically has a sensing element such as a temperature sensitive resistor inside a sheath or housing to form a temperature probe. It is desirable to minimize the housing material in direct contact with the temperature sensing element, since reducing the covering material reduces the time constant of the sensor probe. Minimizing material in contact with the sensing element, that is, reducing the material in the outer sheath or housing, can mean that the temperature sensor probe is more susceptible to damage from particles, or other objects carried in the fluid that is passing over the sensor.
The present invention permits reducing the thickness of the sheath or housing for the sensing element making up the temperature sensor probe so that there will be a fast time response, while also reducing the likelihood of damage to the temperature sensor probe from particles or objects carried in the fluid stream moving past the probe.
The present invention relates to a temperature sensor probe assembly that comprises a temperature sensor probe that is mounted on a housing that projects into a fluid stream, usually an air stream. The temperature sensor probe has a temperature sensing element that has a covering or outer shell made with a minimum amount of material surrounding the sensing element. The temperature sensor probe is supported on the probe assembly housing in a through passageway or duct formed in the housing for air flow. A post is positioned in the housing passageway upstream from the temperature sensor probe, relative to the airflow direction, to cause a flow disruption to improve time response and to intercept airborne objects and divert such objects so they flow around the temperature sensor probe and do not strike it.
The upstream post as shown is generally cylindrical, as is the sensor probe. Other cross sectional shapes will work. The size of the deflector post does not have to be the same as that of the temperature sensor probe, so the deflector post or object can be made robust to withstand impact of airborne materials against it. The post also can have a different cross sectional shape from the temperature sensor probe, and can be elliptical, hexagonal, or other selected shape. The post is secured to the housing in the duct or passageway through which air flows. The deflector post protects the temperature sensor probe so the sensor probe can be made with a minimum amount of material surrounding the temperature sensing element such as a temperature sensitive resistor, for improving time response.